Some things that’s helped me was knowing that it’s ok to pause when speaking. Listening to speakers helped me realize that. This will usually in the form of a long inhale (inhaling also gives me a slight calming effect). Also, focusing on intonation helps out too. I know that an idea is not only conveyed through what is spoken, but how it is spoken. Therefore, focusing on upward and downward inflection definitely gives me the upper edge on controlling how I’m speaking. Last but not least, practice. Try reading out loud by yourself for 15 minutes everyday. Doesn’t have to be long. Just has to be consistent.